Very simple to understand interface, but I wonder how suitable it might be for a skilled operator.
If one needed to operate it regularly and quickly, how might it fare to an interface with more closely spaced controls.
I suppose my question is how much of a trade off is there between simplicity and performance in these kind of task bassed interfaces.

Reminds me of the light switch arrangement from Donald Normans book the design of everyday things. Using a floor plan drawn onto the switch pannels base and switches placed where the lights appear in the corners of the room.